Iminosilanes of various kinds are known in the art and are known to be useful as, among others, intermediates for the production of amine-containing compounds and silylated polymers, adhesion promoters for coating, adhesive and sealants and as coupling agents for mineral filled composites.
Among the known imino-functional silanes and methods for their preparation are the aldimino-functional silanes, ketimino-functional silanes and preparative methods described in U.S. Pat. No. 2,942,019; the N,N′-bis[(tri(substituted)silylalkylene]-1,4-xylene-a,a′-diimines and preparative methods described in U.S. Pat. No. 3,681,420; the imino-functional silanes and preparative methods utilizing isocyanates described in U.S. Pat. No. 5,134,234; the aldimino-functional silanes and ketimino-functional silanes and preparative methods described in U.S. Pat. No. 5,739,201; the imino-functional silanes and amine exchange preparative methods described in U.S. Pat. Nos. 6,586,612 and 6,998,449; the aldimino-functional silanes and preparative methods described in U.S. Pat. Nos. 7,906,673 and 8,877,955; the ketimino-functional silanes and preparative methods described in U.S. Pat. No. 7,923,572; and, the amino-functional silanes (“activated silanes”) and preparative methods described in WO2009/043599. The contents of each of these patent publications are incorporated herein in their entirety.
Imino-functional silanes undergo addition reactions to form imido- and amino-functional silanes and these imido- and amino-functional silanes may further undergo deamination reactions to form conjugated carbon-carbon double bond containing imino-functional silanes. These undesirable reaction products reduce the content of the desired imino-functional silanes, may generate color making them unsuitable as intermediates or adhesion promoters for clear compositions and curtail their storage stability. Because of these adverse effects on product purity and storage stability, a need has arisen for a method of inhibiting, suppressing or preventing the reactions of imino-functional silanes with themselves and the subsequent deamination reactions.